Merge pull request #1691 from ceph/wip-8139

osd_types: pg_t: allow is_split to handle checks for splits prior to the most recent

Reviewed-by: Samuel Just <sam.just@inktank.com>

diff --cc src/osd/PG.cc
Simple merge

diff --cc src/osd/osd_types.cc
Simple merge

diff --cc src/osd/osd_types.h
Simple merge